using UnityEditor;

[CustomEditor(typeof(ImageEx),true),CanEditMultipleObjects]
public class ImageExEditor:UnityEditor.UI.ImageEditor {

    public override void OnInspectorGUI() {
        base.OnInspectorGUI();
        EditorGUILayout.Space();
        ImageEx image = target as ImageEx;
        image.gray = EditorGUILayout.Toggle("Gray",image.gray);
    }

}